Attachment cord anchorage with ball contact switch



'Nv.23,194s. S, P, MORSE y n 2,454,667

ATTACHMENT CORD ANCHORAGEWITH BALL lCONTACT SWITCH Filed June 7, 1945 2 sheets-sheet 1 INVENTOR 5M om.

BY l, 1

j y ff:

ATTORNEY s. P. MORSE 2,454,667 ATTACHMENT CORD ANCHORAGE WITH BALL CONTACT SWITCH Nov. 23,

Filed June 7, 1945 R. m m m Afro/Mfr Patented Nov. 23,d 12948y 2,1454g6c7 ATTACHMENT CORD ACHRAGE W'iii BALL CONTACT SWITCH' Shirley P. Morse.. East Haven; Gonna-assigner to The-A. Gilbert CompanygNew Haven, Conn., ay corporation" of- Maryland Appii'cation .fune 7'. 1945;` serial Nc: tdt-998i 6 Claims. (Cl. 26o- 151)- This invention relates to lianfd` held bodily maneuvered electrical!` appliances and patrlcu'elarly to arrangements of electric switchingV mech-l anism therein combined with attachment cordl anchorage structure of the general type disclosed. in my copending application Seriali No. 553,826',-V led September 13, 1944, now Patent Number 2,432,067, issued December 2, 1947.

In said patentA there is proposed an arrange'- ment of working parts of anl electric" switch so"4 organized in juxtapositioi-i'y to a rugged protec-l tive anchorage for an electric attachment; ccidl entering the appliance that botlr may" combine to form a torpedo-shaped end of' an' appliance having a tapering streamlined outer C'Or-itout: The constructions there` proposed contemplate in one form a hollow cup-shaped', switchi oper'at` ing, ring handle given rotary bearing oni the' peri-e pherey of the torpedo-shaped casing of the appliance in conjunction with a spring-urged pressor plate in axially outboardrelationtol suoli ring handle operative conductivly to bridge' rolling switch contact balls' andi tobiaissu'cll balls"` into engagement with stationary c'ircuitf contaets".

in other` forms disclosed in thev above said patelitV it is proposed to provide 'the ring' Handle' with'. a central bearing hub and to house s'i'i'chA spring' urged pressor plate within the cup-shaped interior of the hollow ring handle ofV tl'ief while ringed about such bearing liu the pressor plate and' its biasing spr ried by and revolve bodily with tlfie'r g" har-idler and the contact balls of the switcl'ilwhen manually actuated.

The present' improvements aim tov combine the comparative simplicity and compac'tnessof appliance casing structure that characterizes the` last mentioned arrangement with certain desir'd mechanical and electrical functions of a` springurged pressor plate which according to the prie'd sent improvements may or need' not' lturnI in unison with the switch handle and ther'ollingl switch contact balls. Movement of suchv ballsv over a circular path relative to a non-turning?? ball-bridging conductive presso'r plate enables shallow sockets or holes inthe plateto serve asV stationing detents for the balls and mayfrttier. serve to wipe clean the mutually` contacting surfaces of balls and plateV as well asf to contributev mechanically to the abruptrle's's of snap actionwlth which the balls make and brealtf contact-- with the stationary circuit terminals of the? switch. y 1

The present improvements alsolp'ermit a greater` area' of current conducting. contact. between- 2. rolling contact ballsl and a ballbridging. pressor plate that maybe conta-ined within the hollow ot euppedfshape switch operating ring handle by enabling theballs to bel seated inspherically con-r r, toured dents',- or in holes of smaller diameter than the balls, provideduin the pressor plate.

Thes-ef and other objectives will: be made clear in: the' following: description` of` one embodiment of the present improvements illustrated in the accompanyingdrawings wherein:

Fig, l. is View` taken mostly in section on planeV I^-l in Figi.y rextending lengthwise through the stub end of an encased portable electrical appliance incorporating av control switch and attach# ment cord anchorage structure embodying the present invention.

Fig.. 2 is a View similar to Figi. 1- taken'in` section on the planes 2"-2 in Fig", 5' looking in theu direce tionof the a'rowsl Fig.I 3` is. a crosswise view takenin section through the ring handle of the'` switch on the plane.` 3e-"3 'in- Fig.` 1 looking ir'r ther direction-ot thev arrows:

Figiv 4f isv aV crcisswise'vr View taken: section through the switch retaining, nut on the plane 4&4 in Figi.. 2f looking the direction` of` the aifrws. l

Fig. 5` is a crosswise4` view takenl in sectioni through the stub' endfof the casing on the pla-ne 5&5. in. Fig. 1V looking in4 the' direction of the arrows'.

Fig. 6 is an exploded perspective'view` ofcertain operating parts of the. s-witclr removed. from the stubi end .of` the appliance;

Fig.. 'T is an illustrative diagram of circuit connections.

Fig'. 8" is a. perspective View ot a noneturnable pressor platey that may be4 substituted: for the turnable` presserplatei of Fig'. 6 in oorljunctioir` withcasingstop projections# modified t cooperate` therewith as key studs.

The housing" of thetnopliancefincludes` a= hollow casirrg` l2 of which only a stubend. portion isl herein shown. In` keeping with modern designl the entirey casing may be elongated and streaiii. lined in outer contour tol terminate in av torpedo osenshape ais-shownin theV drawings; Reference: is made to my copending application,- Serial-.Noi 553,826; filed September` 13,l 1944s,. now Patent# Number 2,432,067, for a full showing of al casing' of this type which lends'. itself` to` being molded from` any suitableelectrical insulati-ve material including the` manly .so-called plastics Preiicrably the casing is of suitable crosswise girth to begraspeddn th'efpalml oi the hand and encircled by the operators iingers for holding and maneuvering the appliance.

That portion of the casing shown in the drawings is longitudinally ribbed internally at I4 to receive the body of an electric motor I5, one end of which is firmly but detachably secured by holding screws I1 to anchorage lugs |6 formed internally on the casing wall. At the opposite end of motor I5 there is a projecting motor shaft (not shown) together with operating connections to the movable parts that perform the working duty of the appliance, such as a'blower fan in a portable hair drier, a projecting drill spindle, a hair clipping blade, or any analogous working tool. Motor I5 is fed with current through the wires 49, 53 of an attached cord 22. The aforesaid copending application may bev 4referred to for illustrative construction of a more complete appliance in which the present improvements may be incorporated to advantage.

The stub endof the casing I2 carries an assemblage of electric current switching parts and attachment cord anchorage structure embodying the present improvements. For the particular objectives of this invention, casing I2 terminates at a transverse or crosswise extending detachable web wall 20 which may be of the same kind of insulative material as the casing and secured to the latter by the same holding screws I1 that have threaded engagement with the body of electric motor I5. Web wall 2U is centrally brushed by an axially elongated rigid tubular conduit structure inclusive of member 2| and xedly lodged therein. This conduit member may be of metal or of insulative material and may be held rigid with wall 28 by vbonding it fixedly therein during the molding operation by which wall 2B is formed. If preferred, conduit member 2| may be formed as a molded homogeneous extension of the insulative material of wall 20. In any event, it affords what may be termed a hollow boss projecting outward from the stub end of casing I2 constituting conduit structure one end of which opens outside the casingv and the other end of which opens to the interior of the casing.

The attachment cord 22 is armored at its appliance connecting end by a molded sheath 23 of flexible resilient insulative material and this sheathterminates in an outilaring flange 24 that overhangs the inner end of tubular member 2| to prevent withdrawal of the attachment cord outward'from conduit member 2|.

The upper or inside face of web wall 2U has xedly secured thereagainst by rivets'21 the binding-posts 23 comprising bent metal clips to which electric circuit wires may be attached by soldering or otherwise. An electric'circuit that includes such wires and the lmotor |5 is diagrammed in full lines in'Fig. 7. The opposite headed-over ends of rivets 21' are sunken alittle in counterloores 29 at the outer mouths of Vholes in web wall 28 through which the rivets extend. There are additional and similar counterbores which may be left blank or vacant of rivet heads, Yas shown at 3|. All of the counterbores are spaced circumferentially in a common circular track concentric with the common longitudinal central axis of casing I2 and conduit member 2|. The rivet heads that are exposed on the outer side of wall 3l) constitute circuit terminals and the rivets 21 serve as conductors leading to the inner side of wall 20 where they are in electrical connection with the attachment cord wires through binding posts 28.

The movable contacts, or circuit making and breaking elements, of the switch include electrically conductive balls 35 of equal diameter adapted to seat fully on the bottoms of the counterbores 29 and/or 3| so as to reach and make electric contact with any heads of rivets 21 that occupy such counterbores. Contact balls 35 are maintained at constant spacing from one another in their circular path of travel regardless of what positions they all occupy along such path due to 'each ball being caged in a slightly oversize hole 36 in a ball impelling disc 31 which is removably fixed in the peripheral rim portion of a ring-like switch handle 38 and thus comprises means for transmitting motion from handle 38 to balls 35 in unison. This handle is hollow and molded from insulative material to a shape providing the hub 39 and the Ventilating apertures 40. Thus ring handle 38 is cup-shaped.

Hub 39 sleeves over and has its sole rotary bearing on the peripheral surface of a rabbet 4| formed in a stationary retaining nut 42 of insulative material that has screw engagement with the threaded outer end of conduit member 2|. Thus switch handle 38 is centered with and separated radially from conduit structure 2| and derives axial retaining thrust from the anged head 43 of nut 42 at rabbet 4|. The parts just described are so dimensioned that when nut 42 is screwed up tightly against a stop shoulder on conduit member 2| there is suicient axial clearance for ring handle 42 to swivel freely between the stationary nut flange 43 and the stationary web wall 20. Nut 42 thus serves as a head for structure 2| in outboard relation to cross wall 20 permitting free turning of handle 38 relatively thereto.

To render the ball impelling disc 31 removable from the body of switch handle 38 for purposes of assemblage it may be fastened thereto by screws, screw threads or equivalent means not shown. This permits a flat pressor plate 45 of conductive material to be received and loosely housed in the hollow space within switch handle between the ball impelling cage 31 and the handle hub 39. Pressor plate 45 is centrally apertured and has sufficient diametri-cal clearance around a statonary insulative tubular sleeve 45 fitted on conduit member 2| to afford freedom of pressor plate 45 both to rotate and to slide axially. In the assembled relationship of the parts shown in Figs. 1 and 2, pressor plate 45 is thrust constantly against the switch contact balls 35 simultaneously in the direction of the web wall 20 of casing I2 by the action of tensioning means in the form of a short spring coil 41 that loosely surrounds sleeve 46 and is circumferentially interposed between conduit member 2| and switch handle 38 in a manner to extend axially from plate 45 to head nut 42, and thereby derive thrust directly from the latter independently of the switch handle. Thus spring 41 is constantly compressed axially :between pressor plate 45 and the thrust nut 42. Spring 41 is not imprisoned within the hollow of switch handle 38 and can be removed independently of the latter from the switch assembly. Nevertheless handle 38 does encircle spring 41 and this feature effects considerable saving of axial space.

From the foregoing description of the construction it will be seen that three of the contact balls 35 may, inan off position of the rotary switch handle 38, occupy three of the vacant counterbores 3| in the insulative web wall 20. The motor I5 is then deprived of current and idle as indicated by broken lines in circuit diagram of Fig. 7. Upon turning switch handle 38 a suit.-

aangaan wire 49 will pass through one of` the binding posts 28, its holding rivet 21, a contact -ball 35, pressor plate 45, another contact ball 35', another rivet 21, another binding post 28, lead. wire 50, and thus through motor I whichf is constantly in'` circuit with the return wire 5l cord. Now motor ate to drive the until such time as the switch handle 38 is: turned back to its olf or starting position. Theturm ing of switcvh handle 38 in either direction beyond the aforesaid off and on positionsmay` or' need not be restricted. by anysuitable forms of. stops such as the projections 52 fixed on web wally to engage opposite ends. of the arcuately elongated notches 53 in ball impelling` cage 3.1 of the switch handle.V

As the contact balls 35 are swung in unison they become seated or unseated simultaneously with respect to their` respective counterbores. In being forced to roll in a common circula-r path by the loosely engaging impelling cage 31: each ball, because of the seating pressure of spring 41 acting through pressor plate l5 and because of the sharp rim edge of each counterbore 29 or 3l, offers resistance to leaving itsseat in the' counterbore up to the point where increasing muscular torque manually exerted upon the switch handle builds up a tension in the operators hand. which" finally overcomes this resistance to unseating of the switch balls. Thereupon there results an abrupt popping up of all three balls simultaneously out of their respective counterbores 29 or 3l producing a quick or snap-action circuit` breaking movement of the current controlling switch parts to inhibit electric arcing and pitting of the contacts. The switch balls 35 may be made of bronze, brass or other metal of good electrical conductivity. When the switch balls reach positions for simultaneously dropping into their respective counterbores over the sharp edges of the latter, the aforementioned lateral looseness of fit of each yball in its hole 36 in handle disc 37 permits the axial urge of pressor plate 45 to snap each ball smartly into its terminal engaging or rivet contacting, fully seated position in its counterbore so that quick making as well as quick breaking of the circuit results.

It will fbe obvious in Figs. l and 2 that no sidewise tugging on attachment cord 40 can act in any way to impair or interfere with free action of the circuit making and breaking parts of the switch because the cord is at all times positively constrained by conduit member 2l.

Fig. 8 shows a desirable modification of the stop projections 52 and pressor plate 45 wherein the former are elongated to form key studs 52 extending into the hollow interior of switch handle 38 and occupying stop notches 53 in the pressor plate 45' thus to retentively engage the latter in a manner to prevent its rotary movement while freely permitting its axial movement.' This modied and non-turning form of pressor plate contains ball orienting seats 54 spaced on the circle to align axially with the respective counter bores 2S and 3i so that each ball is in each position thereof engaged not only with one of 'the counterbores but also with one of the seats 54. These seats may comprise merely dents of spherical contour conforming to the surface of the ball od may be holes of smaller diameter than the overall size of the ball. By this expedient the l5 will be energized andi operof thea'ttachmentI working tool of the appliance.

ballsy are'more certain of cox'itactv with their respectivercircuit terminals cr rivet heads 2.1 wipeandkeepy clean. the surfaces ofv pressor` plate 45 with which they contact, and. are` given a greater area: of current conductive` enga-gementwith the pressoir plateffor` lowering electricaly resistance` Among. obvious modifications of other parts. hereindisclosedit isnotedt'he pressor'plate may be. prevented: from.. tuning. by giving its, central-` and equivalents as fall within` the most inclusive,

means of thev claim` language.

I claim:

l. In a handfmaneuvered appliancetol` be sup-4 plied; with current through` an attachment cord, the combination of, a hollow appliance casing',

a tubular conduit structure` open-ingrinto said cas-'- ing. ina manner to' admit andconstrairr ariA attach.-y ment. cord entering the applianca. a wallxextending crosswise said casing fixedly'joining said con`` duit structure and said casing in substantially rigid. relation.

controlling spacedv positions. llxedl on the outer end ofy said a hollow cup-shaped switchhandle between said wall andsaid retaining head including means to= irnpelV said contact balls between their; said posi-` tions; ai current conductive pressor platev loosely a retaining head conta-inedin the hollow of said, switch, handley bearing against said balls, and: a spring thrust-- ing axially againstsaid retaining head arranged tobiassaid pressor platetoward said* balls'.v

2. In a hand-maneuvered appliance to be supplied with current through an attachment cord, the combination dened in claim 1, together with rotation preventing means stationary with the said crosswise extending wall projecting into the said hollow of the said switch handle and retentively engaging the said pressure plate in a man- `ner to prevent rotary movement and permit axial movement of the latter.

3. In a hand-maneuvered appliance to lbe supplied with current through an attachment cord, the combination defined in claim 1, in whi-ch the said pressor plate carries ball orienting seats receptive to the said contact balls, together with rotation preventing means stationary with the said crosswise extending Wall projecting into the said hollow of the said switch handle and retentively engaging said pressor plate in a manner to prevent rotary movement of the latter.

4. In a hand-maneuvered appliance to be supplied with current through an attachment cord, the combination of, a hollow appliance casing, a 'tubular conduit structure opening into said casing constructed and arranged to admit and constrain -against sidewise tugging an attachment cord entering the appliance, a wall extending crosswise said casing xedly joining said conduit structure and 4casing in rigid relation, at least one circuit controlling electric switch element making andi. breaking.'

simultaneously, are enabled te` paced current conductiveV Contact balls shiftable simultaneously between circuit conduit structure,

7 shiftable between spaced positions, a retaining head xed on said conduit structure in outboard relation to said wall -carrying a circumferential rotary bearing surface, a switch handle free to be turned relatively to said wall rotatably centered by swiveling engagement with said bearing surface, and motion transmitting means movable by said handle impellingly related to said switch.

element for shifting the latter between its said positions, together with a spring coil of smaller girth than said bearing surface arranged to exert electric contact-making pressure -on said switch element and circumferentially interposed between said conduit structure and said switch handle in a manner to extend axially from said switch element to said head thereby -to derive thrust directly from the latter independently of said switch handle.

5. In a hand-maneuvered appliance to be supplied with current through an attachment' cord, the combination of, a hollow appliance casing, a tubular conduit structure opening into said casing constructed and arranged to admit and constrain against sidewise tugging an attachment cord entering the appliance, a wall extending crosswise said casing fixedly joining said conduit structure and casing in rigid relation, a plurality of circuit controlling electric switch elements shiitable in unison Ibetween spaced positions, a retaining head fixed on said conduit structure in outboard relation to said wall carrying a circumferential rotary bearing surface, a switch handle free to be turned relatively to said wall rotatably centered by swiveling engagement with said bearing surface, motion transmitting means movable by said handle impellingly related to said switch element for shifting the latter between its said positions, and tensioning means for exerting electric contact-making pressure simultaneously on said switch elements including a presser plate encircled by said switch handle and a spring coil thrusting axially against said retaining head arranged to bias said presser plate toward said switch elements, said spring coil being of smaller girth than said lbearing surface and circumferentially interposed between said conduit structure and said switch handle in a manner` tov extend axially from said plate to said head thereby to derive thrust directly from'the latter independently of said switch handle.

6. 1n a hand maneuvered appliance incorporating an electric circuit adapted to be supplied with current through the wires of an attachment cord, the combination of, a hollow appliance casing, a conduit structure having one of its ends opening outside `oi said casing and its other end opening into said casing for admitting an attachment `cord therethrough to the interior of Ithe casing, a wall extending crosswise said casing xedly joining said conduit structure and said casing in substantially rigid relationship, at least one conductor presenting an exposed circuit terminal on the outer side of said wall and leading to the inner side of said wall and thereat connected with a wire oi theattachment cord, at least one circuit controlling electric switch element shiftable at said outer side of said wall into and out of engagement with said circuit terminal, a retaining head fixed on the outer end oi said conduit structure presenting a rotary bearing surface, a switch handle separated radially from said conduit structure rotatably sleeved von said bearing surface for turning movement relative to said casing and axially constrained by said retaining head, and motion transmitting means movable by said handle impellingly related to said switch element for shifting the latter into and out of engagement with said circuit terminal.

SHIRLEY P. MORSE.

REFERENCES CITED rIhe following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 718,405 Wagner Jan. 13, 1903 '761,563 Wagner May 31, 1904 1,410,855 Veneria Mar. 28, 1922 2,048,577 Thornton July 21, 1936 2,119,220 Scruggs May 3l, 1938 2,293,015 Cohen Aug. 11, 1942 

